1. Field of the Invention
The present invention relates to semiconductor devices, and particularly to a microelectromechanical systems (MEMS) tunable vertical-cavity semiconductor optical amplifier.
2. Description of the Related Art
Telecommunications has become a part of everyday life. The use of radio frequencies to transmit cellular telephone calls, satellites to deliver television and data service, and the use of wires to transmit voice, data, and video has become commonplace. Many of these systems, at some point, rely on optical fibers to deliver the data, since a single optical fiber can carry many times the data as a single copper wire. To deliver the data, optical amplifiers are required to transmit and amplify the data through the optical fibers in such communications systems.
However, optical amplifiers are typically expensive devices, and are also typically designed to work in specific wavelength regions. These amplifiers, if tunable at all, are not tunable over a very large range, and thus, multiple amplifiers are required for a given installation, driving up costs. Wavelength Division Multiplexing (WDM) networks are optical networks where multiple wavelengths are used. However, in addition to optical amplification, WDM systems require some form of tunable filters for channel selection and reconfigurability.
Long-wavelength vertical-cavity semiconductor optical amplifiers (VCSOAs) are attractive as a low-cost alternative to erbium-doped fiber amplifiers (EDFAs) and conventional in-plane SOAs for use in fiber-optic communications systems. However, the VCSOAs that are typically available are not tunable, and thus, even though VCSOAs are less expensive, multiple VCSOAs are still required for a given installation. A tunable VCSOA can act as a tunable filter, with the added benefit of optical gain, which allows the device to make up for its own insertion loss.
It can be seen, then, that there is a need in the art for tunable optical amplifiers. It can also be seen that there is a need in the art for a tunable VCSOA which can reduce system costs.